Table 2. Relative risk (95% CI) of cardiovascular disease according to frequency of bowel movements in the Nurses’ Health Study (1982–2012)*.
| Frequency of bowel movements |
P for trend† | |||||
|---|---|---|---|---|---|---|
| >1/Day | Daily | Every 2 days | Every 3–4 days | Every 5 days or less | ||
| Cardiovascular disease | ||||||
| Cases/person-years | 1000/233698 | 4898/1457217 | 1163/430390 | 485 /173564 | 82/29053 | |
| Model 1‡ | 1.25 (1.16, 1.33) | 1.00 (reference) | 0.91 (0.85, 0.97) | 0.95 (0.86, 1.04) | 0.93 (0.74, 1.15) | <0.001 |
| Model 2§ | 1.15 (1.07, 1.23) | 1.00 (reference) | 0.94 (0.88, 1.01) | 0.97 (0.88, 1.06) | 0.94 (0.75, 1.17) | <0.001 |
| Model 3|| | 1.13 (1.05, 1.21) | 1.00 (reference) | 0.94 (0.88, 1.00) | 0.96 (0.87, 1.05) | 0.93 (0.75, 1.16) | <0.001 |
| Model 4# | 1.05 (0.98, 1.13) | 1.00 (reference) | 0.96 (0.90, 1.02) | 0.98 (0.90, 1.08) | 0.96 (0.77, 1.19) | 0.04 |
| Coronary heart disease | ||||||
| Cases/person-years | 493/234078 | 2458/1459037 | 593/430801 | 235/173736 | 38/29086 | |
| Model 1‡ | 1.22 (1.11, 1.34) | 1.00 (reference) | 0.92 (0.84, 1.00) | 0.91 (0.80, 1.04) | 0.85 (0.62, 1.17) | <0.001 |
| Model 2§ | 1.12 (1.01, 1.23) | 1.00 (reference) | 0.96 (0.88, 1.05) | 0.93 (0.81, 1.06) | 0.86 (0.63, 1.19) | 0.003 |
| Model 3|| | 1.10 (1.00, 1.21) | 1.00 (reference) | 0.96 (0.87, 1.04) | 0.91 (0.80, 1.04) | 0.86 (0.62, 1.18) | 0.004 |
| Model 4# | 1.00 (0.90, 1.10) | 1.00 (reference) | 0.98 (0.90, 1.07) | 0.95 (0.83, 1.09) | 0.89 (0.64, 1.22) | 0.57 |
| Stroke | ||||||
| Cases/person-years | 516/234029 | 2502/1458849 | 583/430814 | 256/173748 | 44/29077 | |
| Model 1‡ | 1.26 (1.15, 1.39) | 1.00 (reference) | 0.90 (0.82, 0.98) | 0.99 (0.87, 1.12) | 0.98 (0.73, 1.32) | <0.001 |
| Model 2§ | 1.16 (1.06, 1.28) | 1.00 (reference) | 0.93 (0.84, 1.01) | 1.01 (0.88, 1.14) | 0.99 (0.74, 1.34) | <0.001 |
| Model 3|| | 1.15 (1.04, 1.27) | 1.00 (reference) | 0.93 (0.85, 1.02) | 1.01 (0.88, 1.14) | 0.99 (0.73, 1.34) | 0.001 |
| Model 4# | 1.10 (1.00, 1.22) | 1.00 (reference) | 0.94 (0.85, 1.02) | 1.02 (0.90, 1.16) | 1.00 (0.74, 1.35) | 0.03 |
*Cardiovascular disease was defined as coronary heart disease (symptomatic nonfatal myocardial infarction or fatal coronary heart disease) and stroke (nonfatal or fatal).
†P for trend was assessed by assigning the mid-point value in each category to participants and evaluating this as a continuous variable.
‡Adjusted for age.
§Further adjusted for ethnicity (Caucasian, yes/no), menopausal status (pre or postmenopausal (never, past, or current menopausal hormone use)), smoking status (never smoked, pack-years: 1–10, 10–24, 25–44, or ≥ 45), physical activity (hours/week: ≤ 1.0, 1.0–3.5, 3.6–6.0, or ≥ 6), family history of myocardial infarction (yes/no), baseline history of hypertension, hypercholesterolemia, or ulcerative colitis (yes/no), cholecystectomy (yes/no), and use of multivitamin, aspirin, other nonsteroidal anti-inflammatory drugs, thiazide diuretics, and thyroid hormone (yes/no).
||Further adjusted for alcohol intake (g/d: 0, 0.1–4.9, 5.0–14.9, 15.0–19.9, 20.0–29.9, or ≥ 30), Alternate Healthy Eating Index score (quintiles), dietary intake of total fiber (quintiles), and total energy intake (quintiles).
#Further adjusted for body mass index (kg/m2: < 23, 23–24.9, 25–26.9, 27–28.9, 29–30.9, 31–32.9, 33–34.9, 35–36.9, 37–38.9, 39–40.9, 41–42.9, 43–44.9, or ≥ 45) and baseline history of diabetes (yes/no).